Pretty good game. Very much like TES4 only with guns, but that makes sense since it is on the same engine.
If I have a complaint, it's that 1: The main story quest is really short, and 2: Holy freaking bugs batman. The game is amazing, but it's quite possibly the most unstable piece of software I've installed in a very long time (14 memory leaks?? Come on...). And Bethesda definetly used more than a simple disk check for DRM (run X-Fi codecs, and play Fallout, and you'll get some unhappy).
But, despite the bugs, the game is very well done. I absolutly love the way bethesda created the atmosphere in places like Vault 106 and Vault 87. I think they toned it down a bit too much from Fallout 1 and 2, but hey it's still a fun and entertaining game.